The list of the top 15 ISPs may surprise you. There's a reason for this. It's because of how Speedtest.net gathers data.

Based on our index number, which weights download speed as 80 percent of importance and upload speed at the remaining 20 percent, the top three performers are all major cable companies: Cox, Comcast, and Charter Communications. Each is a national provider that can be found in multiple states, and each has serious infrastructure installed to homes. All scored a fantastic average of 18+ Megabits per second (Mbps) for downloads; Cox had the best upload speed of the three, with an average of 4.8 Mbps. Given our weighting, they all got scores of over 15, with Charter at the low end because of the slower upload speed.

What may confuse you are the Verizon results and here's why: When users of any Verizon service use Speedtest.net—whether it's Verizon FiOS using fiber optic technology or DSL via copper phone wire—the results are all tabulated together. Despite this, Verizon still got an amazing 14.80 index score. It's clear that FiOS's speed floats Verizon above the rest. Our Readers' Choice Awards 2011 for ISPs revealed that you, our readers, utterly adore FiOS service. It's won the Readers' Choice award for several years running. That aside, there's no question that Verizon FiOS deserves an Honorable Mention as a fastest ISP technology. FiOS is used by 4.3 million people in 12 states, plus D.C., promising speeds as high as 35 Mbps up and down in some areas. (Next year, Ookla hopes to break out the different technologies for each ISP, as others, like AT&T, also offer multiple connection types.)

Take a look at the very close index scores from Insight and Road Runner, both of which are close to 12.5. Surprised it doesn't say "Time Warner" instead of Road Runner? That's because Time Warner, while the main provider of the Road Runner service in several states, also licenses the network out to other ISPs, including Brighthouse Networks (which didn't make our cut based on number of times tested) and...Insight! In fact, they work well enough together that Time Warner is buying Insight for $3 billion, even though Insight only uses Road Runner in one city: Columbus, Ohio. Insight also operates in Kentucky and some of Indiana and obviously does very well.

Finally, note that Cablevision, which operates Optimum Online in the tri-state area and parts of Pennsylvania, bought out Bresnan Communications last year, which operates in Colorado, Montana, Utah, and Wyoming. Speedtest.net IDs the users there as Bresnan customers still, but the actual service is now called Optimum West. In the test however, the original Optimum scores a good 4.4 index points better than its western counterpart.

How does the overall Net Index stats list differ? Not too much. Comcast, Charter, and Cox still make it in the top four, but are joined there by Optimum Online. The overall test speeds max out with Comcast's 17.55 Mbps average nationwide, compared to the 18.64 Mbps download we saw in PCMag reader tests.

The Fastest ISPs in the Nation:

Cox Communications(18.51 Mbps Down/4.80 Mbps Up)It's the third-largest cable provider in the U.S. with 3.5 million Internet subscribers in 17 states. It's only a tick behind Comcast for downloads, but bested it in upload speeds on average, with an almost identical index number of 15.77.

Comcast Cable(18.64Mbps Down/3.94 Mbps Up)The largest cable operator in the nation, Comcast provides service to 14 million Internet subscribers in 39 states, plus the District of Columbia. Obviously, it knows something about a fast infrastructure based on the speeds it delivers to PCMag readers.

Eric narrowly averted a career in food service when he began in tech publishing at Ziff-Davis over 20 years ago. He was on the founding staff of Windows Sources, FamilyPC, and Access Internet Magazine (all defunct, and it's not his fault). He's the author of two novels, BETA TEST ("an unusually lighthearted apocalyptic tale"--Publishers' Weekly) and KALI: THE GHOSTING OF SEPULCHER BAY. He works from his home in Ithaca, NY.
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